Behavioral interventions will be used to improve adherence to health behavior change programs. In the first program, 150 obese subjects will receive a behavior modification program for dietary control in a 3 x 2 factorial design. All subjects will be married and will be in one of three family support conditions: cooperative spouse-couples training; cooperative spouse-subject alone; and noncooperative spouse-subject alone. These conditions will be crossed woth drug (fenfluramine) vs. no drug conditions. Pretreatment and posttreatment lipid analyses will be performed to determine the influence of weight loss on lipid changes. Bloods will be analyzed for high density lipoprotein (HDL) levels and the other relevant lipid fractions. This study should provide the largest sample of subjects losing clinically significant amounts of weight for whom HDL levels been determined. In addition, weekly blood pressures will be taken to determine the effect of weight loss on blood pressure and to evaluate temporal changes in both. The second major study involves adherence to antihypertensive medication regimens. Hypertensive subjects will be assigned to several behavioral treatment groups; one with a standard behavioral package which has never used systematically with this population, another with a family involvement component, and a third with both.